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Matt Halfhill is crazy about sneakers. He worked in a shoe store as a teenager, buying shoes on clearance. He has charmed his wife with kicks, buying limited-edition pink and red Nikes for her on Valentine’s Day.

He collects them obsessively, lining the walls of his home with about 500 pairs of shoes.

Welcome to the world of the “sneakerhead,” where shoes reign supreme.

Collectors range from casual fans of sneaker fashion to those who buy and sell shoes like a cardboard-encased commodity. True fanatics will camp out overnight for the latest pair, buy multiple pairs (in case one gets scuffed) — and sometimes even wear them.

It’s an obsession that has been gaining traction in recent years, even as sneaker sales have grown only slowly. There are Web sites, magazines, books, movies and radio shows dedicated to sneaker culture. There have even been TV shows, like ESPN2’s “It’s About the Shoes,” that included tours of collectors’ enormous closets.

“I think people are more aware [of sneaker culture], the general public, because of the media and Internet,” said Alex Wang, creative director for Sole Collector magazine and admitted shoe aficionado.

Sneakers have been a part of urban culture for decades. Run DMC rapped about “My Adidas” in the 1980s, and it remains a part of hip-hop culture with famous sneakerhead artists like Missy Elliot and Fat Joe.

But sneaker love has spread. British teen pop star Lilly Allen sings about her “trainers” and rocks them onstage while wearing a posh dress.

Everyone from Manhattan businessmen to Midwestern teens are coming in with a hankering for shoes, store owners say.

“You can tell so much about a person by what they have on their feet,” said Andre Speed, 36, at a Portland specialty sneaker store called Lifted. “You might not have the freshest outfit, but if you have the kicks, you are going to get the respect.”

Shoes can cost hundreds and even thousands of dollars, depending on their cachet.

“The scene is on fire,” Mr. Speed said.

Shoemakers are feeding off the energy. They work with artists to develop specialized pairs, such as Puma’s electric blue and red trainers designed by Brazilian artist Frederico Uribe. There are stores where people can order styles of their own.

Adidas released 30 NBA Superstar shoes — one for each team in the NBA — in December. Shoes flew off the shelves.

In February, the company will offer several player-specific shoes, like a Tim Duncan pair that incorporates his tattoos into the design and will only be available at the NBA All-Star weekend in Las Vegas.

Nike celebrated the 25th anniversary of its Air Force 1 last month with a huge party in New York, where 1,040 different versions of the shoe were on display. One attendee described it as “awesome, out-of-control awesome.”

MTV last week aired highlights of the party as part of a special on the culture surrounding Air Force 1.

Some sneaker designers have become celebrities themselves, such as Tinker Hatfield, Nike’s legendary leader of the Innovation Kitchen, who is the star of sneakerhead events.

Adidas has heard from university equipment managers who get calls from sneakerheads looking for shoes that aren’t available to the public.

“It’s absolutely amazing. Even if it’s the smallest niche, they’ll buy all of them,” said Terrell Clark, a spokesman for Adidas USA, based in Portland.

NPD Group, a market research firm, estimates total U.S. footwear sales were nearly $42 billion in 2005, up 9 percent from the year before. But of that, sales of athletic shoes only grew 3 percent.

Industry analysts say sneakerheads make up a small but crucial part of the shoe industry.

“There is incredible value for how it exists for the company as a tool for them to take a pulse for what kids will see as hip and relevant,” said Paul Swangard, managing director of the Warsaw Sports Marketing Center at the University of Oregon. “You are always trying to find the Pied Piper for the industry.”

Shoe collectors dictate what will be hot and what will be bought.

“Nike gets really great fashion and trend ideas from these kids, who are really cutting edge,” said John Shanley, a clothing and accessories industry analyst for Susquehanna Financial Group. “They can capitalize on [that] down the road from a mass-production mode.”

So shoe companies are compelled to reach out to sneakerheads.

They offer “quick hit” shoes, which might have a hundred or so pairs, and pop-up stores, which open for a day or week to sell a limited-edition shoe and then disappear.

“It’s always changing,” said Dave Ortiz, co-owner of popular New York store Dave’s Quality Meat. “As long as people have feet, they are going to have shoes. Walking around barefoot is not going to come back into style.”

A mix of popular culture, nostalgia, technology and disposable income help drive the increased fascination with sneakers.

“It’s hard to explain to a regular person,” said Sole Collector’s Mr. Wang. “There is always a memory or a story with a sneaker, even if you aren’t into it — you had sneakers at one point.”

Originals like Adidas Shell Toes or Puma classics remain strong. Anything related to Air Jordan, which revolutionized the industry with its mix of style, technology and an iconic player, remains hot more than 20 years after its debut. And some East Coast stores say they are seeing a lot of Vans heading off their shelves lately.

“That is the good thing about sneakers in general,” said Mr. Wang, who prefers running shoes from Asics and Nike. “Everyone has a preference.”

Collectors say they have a hard time specifying why they love their kicks so much.

“My wife thinks I’m crazy,” said Mr. Halfhill, who runs a Web site called nicekicks.com. “She does complain to me to stop talking about shoes all the time.”

But it’s been a financially lucrative obsession for some. They say they could make a down payment on a house or pay off a car loan if they sold their collection — not that they would.

Collecting sneakers is no different than collecting baseball cards or Barbie dolls, said Mr. Wang, who grew up watching basketball and worshipping Michael Jordan.